The static budget, at the beginning of the month, for Onyx Dcor Company, follows: Static budget Sales volume: 1,000 units; Sales price: $70.00 per unit Variable costs: $32.00 per unit; Fixed costs: $37,900 per month Operating income: $100 Actual results, at the end of the month, follows: Actual results: Sales volume: 970 units; Sales price: $74.00 per unit Variable costs: $35.00 per unit; Fixed costs: $34,400 per month Operating income: $3,430 Calculate the flexible budaet variance for sales revenue O A. $3,880 F O B. $3,880 U O C. $4,470 F O D. $4,470 U